Synthesis of covalently-linked phthalocyanine-phthalocyanine and porphyrin-phthalocyanine dimers

Article abstract of DOI:10.1071/CH07449

The synthesis of the dimeric homonuclear phthalocyanines (Pc) 4a, 4b, 5a and 5b and the dimeric heteronuclear Pc 4c and 5c is reported. The reactions are carried out by coupling the monomeric Pc 1a and 1b each containing a phenolic OH group in one of its

Full text of DOI:10.1071/CH07449

RESEARCH FRONT
Full Paper
CSIRO PUBLISHING
www.publish.csiro.au/journals/ajc
Aust. J. Chem. 2008, 61, 273–278
Synthesis of Covalently-Linked Phthalocyanine–
Phthalocyanine and Porphyrin–Phthalocyanine Dimers
Alexey Lyubimtsev,A,B Zafar Iqbal,A and Michael HanackA,C
AInstitut für Organische Chemie, Universität Tübingen, Auf der Morgenstelle 18,
72076 Tübingen, Germany.
BIvanovo State University of Chemistry and Technology, Organic Chemistry Department,
F. Engels Str. 7, 153460 Ivanovo, Russia.
CCorresponding author. Email: hanack@uni-tuebingen.de
The synthesis of the dimeric homonuclear phthalocyanines (Pc) 4a, 4b, 5a and 5b and the dimeric heteronuclear Pc 4c
and 5c is reported. The reactions are carried out by coupling the monomeric Pc 1a and 1b each containing a phenolic
OH group in one of its substituents with the bromoalkyl-substituted Pc 2a,b or 3a,b respectively. From the spectral
data of 4a–c and 5a–c, it can be concluded that in dichloromethane and toluene as solvents, these binuclear Pc are
equilibrating between cofacial and open conformations with the open form predominating. Changing the solvent polarity,
e.g. by adding methanol, the equilibrium is shifted towards a cofacial conformation. Treatment of the Pc 2a,b and 3a,b
with 5-(4ꢀ-oxyphenyl)-10,15,20-triphenylporphin (6) in a basic solution gives the porphyrins (P)-Pc dimers 7a,b and 8a,b
respectively. In dichloromethane, the open conformation is preferred for the P-Pc dimers.
Manuscript received: 28 December 2007.
Final version: 12 March 2008.
Introduction
β-pyrrolic position of the P allow a close proximity of the two
macrocycles.[6]
Multinuclear phthalocyanines (Pc) and porphyrins (P) have
attracted much attention recently because of their potential appli-
cationsascatalysts, semiconductors, andespeciallyasnon-linear
optical materials.[1]
Dimeric Pc structures that are covalently linked by a spacer
and in which the spacer length is systematically varied through a
chain of one to five atoms were studied for the effect of the link-
age length on the interaction between the two terminal Pc. After
reaching a sufficient length of the spacer, a cofacial intramolec-
ular association referred to as ‘clamshell behaviour’is observed,
with a dynamic equilibrium existing between open and closed
arrangements.[2]
One method to synthesize dimeric Pc is a statistical con-
densation of bisphthalonitriles or bisdiiminoisoindolines already
containing the spacer with other substituted phthalonitriles or
diiminoisoindoline.[3,7] Using bisbenzaldehydes, bisporphyrins
with different spacers were synthesized.[5] However, by using
this method, only mononuclear bisphthalocyanines and bis-
porphyrins can be prepared.
Heteronuclear bisporphyrins and bisphthalocyanines can
by synthesized by a step-by-step method. First, substituted
phthalonitrile containing P or phthalocyanin is synthesized.[6a–d]
The subsequent statistical condensation with another phthalo-
nitrile gives dimeric mononuclear or heteronuclear Pc and P-Pc
dimers. P-Pc dimers can be synthesized also from benzaldehyde
containing the Pc-fragment by condensation with pyrrole and
other benzaldehydes.[6e] However, in both cases, the last step
results in low yields of the final products.
Covalently spacer-linked dimeric Pc have previously been
reported by Lever,[3] Torres[4a–c] and our group.[4d] The spac-
ers in these dimeric Pc can be bis-alkoxy groups (e.g.
–OCH2C(CH3)-(R)–CH2O–),[3a–c] catechols with oxygen as
bridging atoms,[3d] methylene chains of different lengths (e.g.
–(CH2)n– with n = 2, 4),[3d] alkynyl chains of varying lengths
(e.g. –(C≡C)m– with m = 1, 2),[4a,c] double alkynyl chains with
m = 2[4b] or mixed alkyl-aryl spacers.[4d]
P or Pc containing a functional group such as OH, NH, or
halogens can also be used directly for dimerization by applying a
bifunctional spacer or by coupling two units.[4,6f,g] In our earlier
work,[4d] we synthesized dimeric homo- and heteronuclear Pc,
starting from unsymmetrical Pc 1a,b, each containing a phenolic
OH group in one of its substituents.
Similar dimeric systems have also been prepared with P taken
as macrocycles instead.[5] Like the dimeric Pc, these P-based
systems are covalently linked with alkyl or aryl groups through
a meso carbon in a pillared cofacial configuration.
We report here the synthesis of Pc-Pc 4, 5 and P-Pc 7, 8 dimers
linked through mixed alkyl-aryl spacers.
The combination of porphyrins with phthalocyanines (P-Pc)
has been especially investigated as light harvesting systems
because of their wider absorption spectrum with respect to
the single macrocycles. As the Pc Q-band is very close to the
fluorescence wavelength of P, an efficient energy transfer from
the P to the Pc occurs after excitation in quite a few P-Pc
dimers. P-Pc dimers that are connected via the meso- or the
Results and Discussion
The synthesis of Pc-Pc 4, 5 and P-Pc 7, 8 dimers is shown in
Scheme 1.The preparation of the starting Pc 1 has been described
by us earlier.[4d] Pc 3a and 3b were also prepared by us in
© CSIRO 2008
10.1071/CH07449
0004-9425/08/040273

RESEARCH FRONT
274
A. Lyubimtsev, Z. Iqbal, and M. Hanack
R
R
R
R
N
N
N
N
N
N
N
R
R
R
R
M
N
1
N
N
N
N
R
R
R
R
(i)
N
M
4
2
6
8
3
N
N
N
2a M ꢀ H2, n ꢀ 3
2b M ꢀ Ni, n ꢀ 3
3a M ꢀ H2, n ꢀ 6
3b M ꢀ Ni, n ꢀ 6
O
7
1a M ꢀ H2
1b M ꢀ Ni
5
O
O
(CH2)n
HO
Br
OH
Pb
N
HN
R
6
NH
R
(ii)
(iii)
N
Pb
Pb
R
R
R
R
N
R
N
N
N
N
N
M
2
N
N
R
N
N
3
2
M
N
N
N
3
N
N
1
4
O
N
R
4
O
R
8
R
8
7
5
R
5
6
6
O
7
4a M ꢀ M1 ꢀ H2, n ꢀ 3
4b M ꢀ M1 ꢀ Ni, n ꢀ 3
4c M ꢀ H2, M1 ꢀ Ni, n ꢀ 3
5a M ꢀ M1 ꢀ H2, n ꢀ 6
5b M ꢀ M1 ꢀ Ni, n ꢀ 6
5c M ꢀ H2, M1 ꢀ Ni, n ꢀ 6
7a M ꢀ H2, n ꢀ 3
7b M ꢀ Ni, n ꢀ 3
8a M ꢀ H2, n ꢀ 6
8b M ꢀ Ni, n ꢀ 6
O
(CH2)n
(CH2)n
7
O
O
6
4
3؅
5
2؅
8
Ph
N
HN
O
R
NH
N
1
R
3
Ph
Ph
N
N
2
N
β
δ
ϕ
11
O
Pc
N
M1
N
N
Br (O-Por)
9
α
γ
ε
N
R ꢀ
O
10
N
β
R
O
R
Br (O-Por)
Pc
α
ϕ
R
R
Scheme 1. (i) Br(CH2)nBr (n = 3 or 6), DMF/THF, K2CO3, 75◦C, 3 h; (ii) 1a or 1b, DMF/THF, K2CO3, 75◦C, 6 h; (iii) DMF/THF,
K2CO3, 75◦C, 6 h.
the same publication. Treatment of 1a and 1b with excess 1,3-
dibromopropane in the presence of potassium carbonate, either
in DMF or in a DMF/THF mixture (1:1), resulted mainly in the
formation of the corresponding bromopropyl derivatives 2a and
2b.As seen byTLC, 1a,b were completely alkylated after a reac-
tion time of 3 h; no starting material was present any more. The
dimeric compounds 4a,b and 5a,b were also formed in small
quantities under the synthesis conditions. They were separated
by column chromatography as the first fraction.
monomeric Pc 1–3 show the typical electronic spectra for metal-
free Pc (1a, 2a, 3a) and metal-containing (1b, 2b, 3b). The
tendency of aggregation in organic solvents (dichloromethane
(DCM), toluene and mixture with methanol) in concentration in
the regions 10−5–10−7 mol L−1 is relatively low.
The 1H NMR spectra of Pc 2a,b and 3a,b exhibit no signals of
hydroxyl protons.Two triplets at ∼4.0 and 3.4 ppm correspond to
four alkyl protons Hα and Hϕ of the bromohexyl or bromopropyl
fragments, and triplets near 2.3 ppm in the spectra of 2a and 2b
correspond to two protons Hβ of the bromopropyl fragment,
whereas the signals of the eight protons Hβ, Hγ, Hδ, and Hε
The alkylation of the hydroxyl groups in 1a and 1b did not
result in any significant change in the UV/visible spectra. All

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Phthalocyanine–Phthalocyanine and Porphyrin–Phthalocyanine Dimers
275
Table 1. Absorption spectra of monomeric 2a,b and 3a,b and dimeric 4a–c and 5a–c phthalocyanines (Pc) in dichloromethane
sh, shoulder
Pc
λmax (log ε)
2a
2b
3a
3b
4a
4b
4c
5a
5b
5c
702 (5.26)
702 (5.27)
702 (5.40)
668 (5.21)
674 (5.40)
668 (5.20)
674 (5.41)
668 (5.23)
671 (5.19)
672 (5.16)
668 (5.20)
671 (5.15)
671 (5.18)
639 (4.76)
645 (sh)
640 (4.75)
646 (sh)
644 (5.23)
629 (5.10)
645 (5.04)
641 (5.02)
629 (5.11)
644 (5.07)
606 (4.50)
607 (4.72)
607 (4.49)
607 (4.71)
610 (sh)
400 (sh)
392 (sh)
400 (sh)
382 (sh)
400 (sh)
395 (sh)
394 (sh)
393 (sh)
383 (sh)
392 (sh)
346 (5.00)
331 (sh)
345 (4.99)
329 (sh)
292 (4.88)
305 (5.11)
292 (4.88)
300 (5.12)
294 (5.18)
301 (5.22)
290 (5.20)
293 (5.00)
300 (5.26)
301 (5.17)
343 (5.31)
700 (sh)
701 (5.16)
331 (sh)
340 (5.10)
611 (sh)
577 (sh)
699 (sh)
331 (sh)
3.0
2.5
2.0
1.5
1.0
0.5
0.0
2.0
1.5
1.0
0.5
4a
5a
1
1
2
3
2
3
4
4
0.0
500
550
600
650
700
[nm]
750
800
850
500
550
600
650 700
λ
[nm]
750
800
850
λ
2.0
1.5
1.0
0.5
0.0
2.0
1.5
1.0
0.5
4b
4c
1
2
1
2
3
3
4
4
0.0
500
550
600
650
700
[nm]
750
800
850
500
550
600
650
700
[nm]
750
800
850
λ
λ
Fig. 1. UV/visible spectra of dimeric phthalocyanines 4a–c and 5a in dichloromethane with 0% (1), 25% (2), 50% (3) and 75% methanol (4).
of the bromohexyl fragment of Pc 3a and 3b are seen in the
1.88–1.25 ppm region and overlap with signals of the peripheral
tert-butyl groups. In the spectra of 2a and 3a, the signals of the
inner NH protons appear at approximately −0.47 ppm.
Dimeric homonuclear 4a,b and 5a,b and heteronuclear 4c
and 5c Pc were synthesized by coupling the monomeric Pc 2a
and 2b with Pc 1a or 1b, respectively.
The dimeric Pc 4a–c and 5a–c are more polar than the start-
ing Pc 1a,b, 2a,b and 3a,b, respectively, and were completely
separated by column chromatography.
The dimeric Pc species may be open, with no interaction
between Pc units, or closed, with Pc–Pc interaction. The mono-
nuclear systems 1, 2, and 3 show visible spectra in organic
solvents typical of monomeric Pc and can be used as models
for the open form of the ‘clamshell’.
The UV/visible spectra of binuclear Pc 4a ∗and 5a in
dichloromethane (Table 1, Fig. 1) show double π-π bands near
700 and 670 nm, but the band near 640 nm exhibits enhanced
intensities compared with the monomers 2a and 3a, typical
for aggregation.[8] In addition, the Ni-Pc 4b and 5b exhibit
bands at ∼670 and 630 nm in DCM, but the bands at 630 nm
are blue-shifted and their intensity is greatly enhanced in com-
parison with absorption in monomeric metal-Pc 2b and 3b,
also typical for aggregation. The aggregation is intramolec-
ular rather than intermolecular as it is almost unaffected by
dilution.
In the 1H NMR spectra of dimeric Pc 4 and 5, signals of four
protons Hα (Hϕ) show a triplet at ∼4.3 ppm for dimers 4a–c and
at ∼4.0 ppm for dimers 5a–c. Two alkyl protons of the propyl
group Hβ in spectra Pc 4a–c exhibit a triplet near 2.3 ppm.
The matrix-assisted laser desorption–ionization time of flight
(MALDI-TOF) spectra of the synthesized dimers 4a–c and
5a–c show the expected molecular weight; no fragmentation was
observed.
In the UV/visible spectra of heteronuclear dimers 4c and 5c
in DCM, the Q-band near 700 nm is seen only as a shoulder

RESEARCH FRONT
276
A. Lyubimtsev, Z. Iqbal, and M. Hanack
4
3
2
1
0
2.5
2.0
1.5
1.0
0.5
0.0
7a
7b
300
400
500
600
[nm]
700
800
300
400
500
600
λ
[nm]
700
800
λ
Fig. 2. UV/visible spectra of porphyrins-phthalocyanines dyads 7a and 7b in dichloromethane.
and the intense broad absorption can be seen between 600 and
650 nm (Table 1, Fig. 1).
DCM or toluene as solvents, these binuclear Pc are in an equi-
librium between a cofacial and an open conformation, with the
open form predominating. The equilibrium between the con-
formations can be shifted towards the cofacial form by adding
methanol to the DCM solution, changing the polarity of the
solvent mixture.
In the P-Pc dimers 7a,b and 8a,b, the open conformation
dominates. The synthesis of these P-Pc dimers was carried out
by the reaction of the Pc 2a,b and 3a,b respectively with the P 6
containing a phenolic substituent.
In summary, the spectral data of dimeric Pc 4a–c and 5a–c
show that in dichloromethane and toluene solution, these
binuclear species are in an equilibrium between cofacial and
non-cofacial conformations with the open form predominating.
We have studied the influence of solvent nature on the
equilibrium between open and closed conformations of the
Pc-Pc dyads 4a–c and 5a–c. We found that an addition of
methanol to solutions of dimeric Pc 4–5 in dichloromethane
changed the character of UV/visible spectra in the Q-band
region. Figure 1 shows the changes of the UV/visible spec-
tra after dilution of DCM solutions of Pc 4–5 with methanol.
In all cases, the absorption between 670 and 700 nm decreases
with increasing concentration of methanol, whereas the absorp-
tion at ∼650 nm increases, which leads to the conclusion that
addition of methanol shifts the equilibrium towards a cofacial
conformation. Comparing the spectra of 5a and 4a (Fig. 1), a
small dependence of the equilibrium on solvent that is greater
for 5a than 4a containing the closed conformation can be seen.
This effect is intramolecular because it is almost unaffected by
dilution with the same solvent mixtures.
Treatment of Pc 2a,b and 3a,b with P 6 in DMF or a
DMF/THF mixture using K2CO3 as base gave the P-Pc dimers
7a,b and 8a,b respectively. The separation of the dimers from
excess P 6 was done by chromatography; no starting Pc 2a,b and
3a,b were detected any more by TLC and MALDI-TOF analy-
sis. The 1H NMR spectra of P-Pc 7a,b and 8a,b exhibit proton
signals of both the Pc and P units. Signals of four protons Hα and
Hϕ in the spectra of P-Pc dyads 7a and 7b show a multiplet near
4.5 ppm. In the spectra of the dimers 8a and 8b, these protons
show two triplets at ∼4.2 and 4.1 ppm because of the different
electronic influence between Pc and P fragments.
Experimental
General
Unless otherwise noted, all starting materials were obtained from
commercial suppliers and used without further purification. All
solventsweredriedbystandardmethods. MgSO4 wasusedtodry
all organic solutions during workup procedures. Analytical TLC
was performed on Kieselgel F-254-percolated TLC plates. For
flash chromatography, silica gel 60 (230–400 mesh) was used.
1H NMR spectra were recorded on Bruker AC 250 and 400
spectrometers. The UV/visible spectra were taken in CH2Cl2
with a Lambda 25 UV/visible spectrometer and IR spectra with a
Nicolet 380 infrared spectroscopy (FT-IR). Mass spectra (FAB-
MS, EI, MALDI-TOF) were obtained on a Finnigan TSQ 70
MAT and a Bruker Autoflex spectrometer.
Pc 2a and 2b. General Method
Compound 1a or 1b (0.016 mmol) was mixed with excess
dibromoalkane in DMF (2 mL; for 1b in a 1:1 DMF/THF
mixture) in the presence of K2CO3 (0.02 g, 0.145 mmol). The
mixture was heated to 75◦C for 3 h. After cooling, the reac-
tion product was added to water/methanol (1:1, 20 mL), filtered
off, washed thoroughly with methanol, dried, and subjected to
column chromatography on silica gel with CH2Cl2/n-hexane
(65:35) as eluent. Pc 2a and 2b were isolated as the largest
chromatographic fractions (second).
The UV/visible spectra of all P-Pc dyads in DCM (Fig. 2) are
combinations of the spectra of individual P and Pc units from
which these have been derived. Addition of methanol to DCM
solutions of 7a,b and 8a,b show only very small blue shifts of
the Q-band. Hence for P-Pc dyads 7 and 8, the open ‘clamshell’
is preferred.
1
Pc 2a: Yield: 0.022 g (69%). H NMR (400 MHz, CDCl3,
3
numbering according to Scheme 1): δ 9.20 (d, J 8.2 Hz, 1 H,
H2), 9.07–9.00 (m, 6 H, H1), 8.83 (d, 4J 1.8 Hz, 1 H, H4), 7.79
3
4
(dd, J 8.4 Hz, J 2.0 Hz, 1 H, H3), 7.38–7.09 (m, 19 H, H6,
12 H9, 6 H10), 6.98–6.74 (m, 3 H, H5, H7, H8), 4.14 (t, 3J
5.8 Hz, 2 H, Hα), 3.58 (t, 3J 6.4 Hz, 2 H, Hϕ), 2.31 (t, 3J 5.8 Hz,
2 H, Hβ), 1.43–1.18 (m, 108 H, H11), −0.46 (s, 2 H, HNH).
UV/vis (CH2Cl2) λmax/nm (log ε) 702.5 (5.26), 668.1 (5.21),
639.0 (4.76), 606.0 (4.50), 400 (sh), 345.5 (5.00), 292.0 (4.88).
m/z (MALDI-TOF) 1970 [M]+.
Conclusions
The dimeric homonuclear Pc 4a,b and 5a,b as well as the
dimeric heteronuclear Pc 4c and 5c were synthesized by a sim-
ple coupling reaction between the monomeric Pc 1a and 1b,
respectively, each containing a phenolic OH group in one of its
substituents, with the bromoalkyl-substituted Pc 1a or 1b. In

RESEARCH FRONT
Phthalocyanine–Phthalocyanine and Porphyrin–Phthalocyanine Dimers
277
1
Pc 2b: Yield: 0.027 g (83%). H NMR (400 MHz, CDCl3,
(4.36), 551.8 (4.10), 517.0 (4.29), 482 (sh), 418.8 (5.55), 348.7
(5.10), 291.6 (4.89). m/z (MALDI-TOF) 2518 [M]+.
3
numbering according to Scheme 1): δ 8.99 (d, J 8.1 Hz, 1 H,
H2), 8.92–8.77 (m, 6 H, H1), 8.63 (s, 1 H, H4), 7.68 (d, 3J 8.3 Hz,
7b:Yield: 0.050 g (77%). 1H NMR (250 MHz, CDCl3, num-
bering according to Scheme 1): δ 8.97–8.75 (m, 7 H, H2, 6 H1),
1 H, H3), 7.38–7.08 (m, 19 H, H6, 12 H9, 6 H10), 6.94–6.74
(m, 3 H, H5, H7, H8), 4.12 (t, J 5.6 Hz, 2 H, Hα), 3.55 (t, J
8.41 (d, J 2.2 Hz, 1 H, H4), 8.39–8.14 (m, 16 H, 8 Hβ, 6 Ho,
3
3
4
3
6.4 Hz, 2 H, Hϕ), 2.29 (t, J 6.1 Hz, 2 H, Hβ), 1.41–1.17 (m,
2 H2ꢀ), 7.75–7.54 (m, 10 H, H3, 9 Hm,p), 7.46–7.07 (m, 21 H, H6,
12 H9, 6 H10, H3ꢀ), 7.02–6.81 (m, 3 H, H5, H7, H8), 4.62–4.42
(m, 4 H, Hα and Hϕ), 2.44 (t, 3J 6.2 Hz, 2 H, Hβ), 1.46–1.27 (m,
108 H, H11), −3.89 (s, 2 H, HNH(porphyrin)). UV/vis (CH2Cl2)
λmax/nm (log ε) 677.0 (4.92), 648.2 (sh), 608.4 (4.32), 551.0
(4.11), 517.5 (4.26), 482.6 (sh), 419.7 (5.37), 329.9 (4.85), 305.6
(4.99). m/z (MALDI-TOF) 2574 [M]+.
108 H, H11). UV/vis (CH2Cl2) λmax/nm (log ε) 674.1 (5.40),
645.0 (sh), 607.1 (4.72), 392 (sh), 330.5 (sh), 304.8 (5.11). m/z
(MALDI-TOF) 2026 [M]+.
Homonuclear and Heteronuclear Dimeric Pc 4a, 4b,
and 4c
Dimers 8a and 8b were obtained by reaction of Pc 3a and 3b
with P 6, respectively.
4a, 4b, and 4c were prepared using the method described by
us earlier for the Pc dimers 5a–c by reaction of alkylated Pc 2a
and 2b with starting Pc 1a and 1b, respectively.[4d]
8a:Yield: 0.047 g (73%). 1H NMR (250 MHz, CDCl3, num-
3
bering according to Scheme 1): δ 9.17 (d, J 8.3 Hz, 1 H, H2),
4a:Yield: 0.054 g (58%). 1H NMR (400 MHz, CDCl3, num-
9.05–8.96 (m, 6 H, H1), 8.81 (d, 4J 1.8 Hz, 1 H, H4), 8.70–8.62
(m, 8 H, Hβ), 8.25–8.18 (m, 6 H, Ho), 8.09 (d, 3J 8.5 Hz,
bering according to Scheme 1): δ 9.06 (d, J 8.1 Hz, 2 H, H2),
3
9.02–8.93 (m, 12 H, H1), 8.71 (s, 2 H, H4), 7.71 (d, 3J 8.4 Hz,
2 H, H3), 7.34–7.12 (m, 38 H, 2 H6, 24 H9, 12 H10), 6.92 (s,
2 H, H5), 6.87–6.80 (m, 4 H, 2 H7, 2 H8), 4.25 (t, 3J 5.6 Hz, 4 H,
2 Hα and 2 Hϕ), 2.30 (t, 3J 6.1 Hz, 2 H, Hβ), 1.40–1.15 (m, 216
H, H11), −0.84 (s, 4 H, HNH). UV/vis (CH2Cl2) λmax/nm (log ε)
702.2 (5.40), 668.1 (5.42), 644.0 (5.23), 610.0 (sh), 400.0 (sh),
343.0 (5.31), 294.0 (5.18). m/z (MALDI-TOF) 3740 [M]+.
4b:Yield: 0.071 g (74%). 1H NMR (400 MHz, CDCl3, num-
bering according to Scheme 1): δ 8.82–8.58 (m, 14 H, 2 H2,
12 H1), 8.57 (s, 2 H, H4), 7.51 (d, 3J 8.1 Hz, 2 H, H3), 7.30–7.10
(m, 38 H, 2 H6, 24 H9, 12 H10), 6.99 (s, 2 H, H5), 6.83–6.77
(m, 4 H, 2 H7, 2 H8), 4.26 (t, 3J 5.9 Hz, 4 H, 2 Hα and 2 Hϕ),
2.27 (t, 3J 5.9 Hz, 2 H, Hβ), 1.36–1.16 (m, 216 H, H11). UV/vis
(CH2Cl2) λmax/nm (log ε) 671.6 (5.19), 629.0 (5.10), 395.0 (sh),
301.3 (5.22). m/z (MALDI-TOF) 3852 [M]+.
3
4
2 H, H2ꢀ), 7.79 (dd, J 8.5 Hz, J 2.2 Hz, 1 H, H3), 7.76–7.64
(m, 9 H, Hm,p), 7.41–7.11 (m, 21 H, H6, 12 H9, 6 H10, H3ꢀ),
6.95–6.83 (m, 3 H, H5, H7, H8), 4.24 (t, J 6.3 Hz, 2 H, Hϕ),
3
4.12 (t, J 6.3 Hz, 2 H, Hα), 2.05–1.30 (m, 116 H, 108 H11,
3
2 Hβ, 2 Hγ, 2 Hδ, 2 Hε), −1.01 (s, 2 H, HNH(Pc)), −3.36 (s,
2 H, HNH(porphyrin)). UV/vis (CH2Cl2) λmax/nm (log ε) 701.0
(5.09), 670.4 (5.07), 644.4 (4.61), 607.4 (4.40), 550.0 (4.05),
514.8 (4.26), 480 (sh), 418.5 (5.59). m/z (MALDI-TOF) 2557
[M]+.
8b:Yield: 0.052 g (79%). 1H NMR (250 MHz, CDCl3, num-
3
bering according to Scheme 1): δ 9.00 (d, J 8.5 Hz, 1 H, H2),
8.92–8.80 (m, 6 H, H1), 8.64 (d, 4J 2.2 Hz, 1 H, H4), 8.57–8.47
(m, 8 H, Hβ), 8.30–8.20 (m, 6 H, Ho), 8.12 (d, 3J 8.5 Hz, 2 H,
H2ꢀ), 7.74–7.61 (m, 10 H, H3, 9 Hm,p), 7.40–7.08 (m, 21 H, H6,
4
12 H9, 6 H10, H3ꢀ), 6.94 (t, t, J 2.2 Hz, 1 H, H5), 6.88–6.79
4c:Yield: 0.064 g (67%). 1H NMR (400 MHz, CDCl3, num-
bering according to Scheme 1): δ 9.01–8.57 (m, 14 H, 2 H2,
12 H1), 8.51 (s, 2 H, H4), 7.66–7.57 (m, 2 H, H3), 7.35–7.03
(m, 38 H, 2 H6, 24 H9, 12 H10), 6.93 (s, 2 H, H5), 6.84–6.77
(m, 4 H, 2 H7, 2 H8), 4.24 (t, 3J 5.9 Hz, 4 H, 2 Hα and 2 Hϕ),
2.28 (t, 3J 6.1 Hz, 2 H, Hβ), 1.37–1.25 (m, 216 H, H11), −1.01
(s, 2 H, HNH). UV/vis (CH2Cl2) λmax/nm (log ε) 700 (sh), 672.3
(5.16), 645.0 (5.04), 394.0 (sh), 331.2 (sh), 290.0 (5.20). m/z
(MALDI-TOF) 3796 [M]+.
(m, 2 H, H7, H8), 4.24 (t, 3J 6.3 Hz, 2 H, Hϕ), 4.14 (t, 3J 5.9 Hz,
2 H, Hα), 2.06–1.31 (m, 116 H, 108 H11, 2 Hβ, 2 Hγ, 2 Hδ, 2 Hε),
−3.73 (s, 2 H, HNH(porphyrin)). UV/vis (CH2Cl2) λmax/nm
(log ε) 675.9 (5.11), 646.3 (sh), 607.4 (4.45), 550.0 (4.15), 514.8
(4.29), 479.5 (sh), 418.5 (5.40). m/z (MALDI-TOF) 2616 [M]+.
Acknowledgement
Zafar Iqbal thanks the Deutsche Akademische Austauchdienst (DAAD) for
financial support.
P–Phthalocyanin Dimers 7a,b and 8a,b
References
Pc 2a,b or 3a,b (0.025 mmol) and 5-(4ꢀ-oxyphenyl)-
10,15,20-triphenylporphin (6) (0.05 mmol) were mixed with
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ture was heated to 75◦C for 6 h. After cooling, the product was
added to methanol (20 mL), filtered off, washed thoroughly with
methanol, dried, and subjected to column chromatography on
silica gel with CH2Cl2/n-hexane (65:35) as eluent.
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